Short answerDry ice placed in water makes a thick, low-lying fog. Use it only in a well-ventilated space or outdoors, handle it with gloves or tongs, keep it out of anything people will drink, and keep children and pets away from it.
Why the fog hugs the floor
Dry ice turns into carbon dioxide gas, which the Compressed Gas Association says is about 1.5 times heavier than air. That is why the effect stays low, and also why the gas can build up in low or enclosed spots. The CGA recommends ventilation that exhausts from the lowest level.
Safety rules for a party
- Ventilate. Columbia Market Food and Dry Ice, a seller, tells customers to use dry ice only in a well-ventilated area or outside. The Illinois Poison Center says carbon dioxide buildup can cause headaches, dizziness and vomiting.
- Never in drinking cups. The Illinois Poison Center says not to place dry ice directly in cups.
- Wear gloves to handle it (Illinois Poison Center); never touch it bare-handed (CGA).
- Keep kids and pets away from the container and the pooled fog.
- Store leftovers in an insulated container, not your freezer (Illinois Poison Center), and never in an airtight one (CGA).
Getting rid of it after the party
Let leftovers turn to gas in a well-ventilated place people cannot reach. The CGA says not to put dry ice in sinks, toilets, garbage cans or areas open to the public.
Where to buy it
Halloween is a busy week for dry ice sellers. Some, such as Dry Ice Pittsburgh, post special hours around it. Call ahead to confirm stock.
Sources (checked October 29, 2026)
- Compressed Gas Association: Dry Ice Safety (SP-15)
- Compressed Gas Association: Carbon Dioxide Safety
- Illinois Poison Center: Halloween Safety (Dry Ice)
- Columbia Market Food and Dry Ice (Columbia Heights, MN)
- Dry Ice Pittsburgh: Retail Location Pickup
General guidance, not professional safety advice. Follow your supplier’s and carrier’s instructions.